High Energy Density Lithium-Ion Cells with Silicon Nanowire Anode Technology

Ionel Stefan

CTO, Amprius Technologies, Inc.1180 Page Ave., Fremont, CA

2020 NASA Battery Industry Day

AMPRIUS TECHNOLOGIES, INC.

COMPREHENSIVE PLATFORMTechnology platform includes entire ecosystem for optimal performance:

BEST PERFORMANCEHighest energy density lithium-ion cells

Silicon nanowire anode manufacturing

Electrochemistry

High energy cell designs

1200 450

100% 50+

Wh/liter Wh/kg

Independent patent filings on nanowire technology

and lithium ion cells

Silicon nanowire anode

Leader in Silicon Anode TechnologyHighest Performance Li-Ion Cells in the Industry

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ENABLING TECHNOLOGYPioneers and established leaders in silicon anode materials and high energy density lithium ion batteries

2008 Company founded at Stanford

2009 Operations Started

2018 First Commercial Product

“Silicon Is Awesome and Inexpensive”- Tesla Battery Day 2020

PATENTED SILICON NANOWIRE ANODE CONSTRUCTIONA New Structure for 100% Silicon Based on Nanowires

KEY BENEFITS- Micro & Macro porosity- prevents cracking

and interference between nanowires

- Tolerates Expansion, Nanowire Rooted-mechanically and electrically connected to substrate

- Stable Solid Electrolyte Interphase (SEI)-stabilized interaction with electrolytes

- Conductive filament grown from substrate

- Bulk coating of low density, porous amorphous silicon

- Thin layer of high-density amorphous silicon

310

340

330

30 µm

8 µm

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MANUFACTURING: ROLL-TO-ROLL FOR SILICON NANOWIRE ANODE PRODUCTIONPilot Scale Manufacturing – demonstrated scalability with Pilot Tool

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200 kWh per line

Bare Foil In and Finished Anode Out• powder mixing

• slurry preparation

• roll coating (2X)

• drying

• calendaring

Replaces:

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Products and Applications

HIGH ENERGY AND POWER CAPABILITYAmprius’ cells enable the highest energy and power

Graphite

Anode Cell

maximum cell

body temperature

during discharge

ENERGY

POWER

Silicon Nanowire//LCO Ragone Plot

6Proprietary and Confidential

Application

Dimensions

(T x W x H)

mm

Mass

g

Capacity

Ah

Energy

WhWh/L Wh/kg

Capacity

Ah

Energy

WhWh/L Wh/kg

Charge-Discharge Rate: C/5-C/5 Charge-Discharge Rate: 1C-3C

HAPS 4.5 x 50 x 55 33.1 3.8 13.9 1125 420

Drones, High

Power4.2 x 50 x 55 27.8 2.8 10.1 875 365 2.65 9.0 780 325

Drones, Long

Endurance4.6 x 50 x 55 31.7 3.6 13.2 1040 416 3.4 11.5 870 360

High-Capacity

Cells4.5 x 50 x 105 68.1 8.1 29.3 1240 430

Army Wearable

Pack5.4 x 54 x 64 49.5 5.4 21 1125 425

PRODUCTSHigh Power capability with highest energy density and specific energy

Operating temperature range: -20ºC to 55ºC. Cycle life 150-300 cycles, depending on operating conditions

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CHEMISTRIES WITH LONG CYCLE LIFELong Endurance Batteries

Si/LCO

80%

Cycling at C/5 for Long Endurance UAV applications

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Si/NMC811

SILICON NANOWIRE ANODE ENABLES MUCH GREATER IMPROVEMENT

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Flight Time Mission Time Talk Time Range

SoA Graphite Amprius SiNW

Urban Air Mobility Soldier Wearable Power

Smartwatch BEV

Notes: UAM – estimated flight time based on customer modelsSoldier Power – real data based on Conformal Wearable Battery developed for US ArmySmartwatch – customer reported dataBEV – estimated relative to Tesla Model 3 long range battery specifications

Game-Changing Advantages in Advanced Applications

15 min

37 min

8.2 h

17.8 h

3.1 h

5.7 h

334 mi

602 mi

USE CASESEnergy Cells for High Altitude Drones Enable Longest Endurance

“The aircraft has achieved an altitude of 74,000 ft in Arizona and, critically, has remained above 50,000ft at dawn, after a

night's flying with no sun to charge its batteries.”

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USE CASESLightweight battery pack for Stratosphere

Target

87%

C/5 Cycling at 30 mBar (~78,000 ft)

• 406 Wh/kg battery pack

• Replaced incumbent Li/S

• Reduced battery size over 50%

• Light-weight, compliant compression system for stratosphere

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x12

USE CASESPower Cells for Urban Air Mobility – Long Endurance

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USE CASESEndurance Record for Multi-Rotor Drone with Amprius Power Cells

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USE CASESLong Endurance Power Batteries

• 415 Wh/kg at C/5, 370 Wh/kg at 2C → doubles endurance• Designed for eVTOL and multirotor drones

725 Wh, 5 lb (2.27 kg) Pack

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HIGH POWER CELLSSmall, long endurance power drones

0%

20%

40%

60%

80%

100%

120%

Discharge Rate

Energy, % vs. C/5

• >80% relative energy to 6C rate

• Small temperature increase and within operating limits to 10C rate

20

25

30

35

40

45

50

55

60

0 0.5 1 1.5 2 2.5 3

Tem

pe

ratu

re (

oC

)

Discharge capacity (Ah)

6C

5C

4C

3C

2C

1C

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PORTABLE POWER APPLICATIONConformal-Wearable Battery – 2X Energy Content

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CONFORMAL-WEARABLE BATTERY2X Energy Content

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Specification CWB-150 (Fielded Model) Ampr ius

“Flexible” battery

Energy (Pack) 148 Wh 320 Wh

Weight 2.6 lb 2.6 lb

Dimensions 8.7” x 7.65” x 0.7” 8.7” x 7.65” x 0.7”

Cells specific energy

201 Wh/kg 395 Wh/ kg

x 16

UN38.3 certified in 2020, confirmed performance in field test

USE CASESEV – Future Market

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EV CELLSExceed 2025 Goals

• Si/NCM811• ISO form factor VIFB-/99/300

Model based on results to date:• Capacity: 60 Ah at C/3 rate (30°C)• Energy: 450 Wh/kg and 1200 Wh/L• Peak Power: 1000 W/kg and 2650 W/L• 80% capacity charged in 15 minutes

50% higher specific energy than best EV cells

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EV PERFORMANCE TESTSCycle Life – Dynamic Stress Test (DST)

• DST pulse profile• Constant energy discharged every cycle

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>650 cycles, ongoing improvement to 1000

>100,000 miles with 200-mile range battery

EV PERFORMANCE TESTSCalendar Life – 50°C at Full Charge

Equivalent to about 8 years, ongoing improvement to 10 years

• Reference Performance Test verification every 32 days

• Calendar Life at 50°C equivalent to about 4x Calendar Life at 30°C

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EV PERFORMANCE TESTSHigh Rate Charge

• Charge for 15 minutes at 3.2C rate

• 85% energy restored in 15 minutes

• 99.5% energy restored in subsequent normal full cycle

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Silicon nanowire anode is best for fast charging due to lower thickness

8 5 % E N E R G Y C H A R G E D I N 1 5 M I N U T E S

HIGH LOADING, HIGH VOLTAGE LCO

HIGH LOADING, Ni-RICH NMC

LARGE FORM FACTOR, ADVANCED CATHODES

HIGH SILICON LOADING, ADVANCED CATHODES, LARGE FORM FACTOR

ROAD MAP: SPECIFIC ENERGY

2019 2020 2021 2022 2023

300

WH/

KGSP

ECIF

IC E

NERG

Y

350

400

450

500

550

600

650

ACTIVE MATERIALS IMPROVEMENT AND ACTIVE/INACTIVE RATIO INCREASE

SILICON NANOWIRE ANODEGRAPHITE ANODE

Thank You

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Ionel Stefan, (510) 512-5484, ionel@amprius.com

Jon Bornstein, (408) 406-2671, jonb@amprius.com

Amprius wishes to acknowledge the funding received from US Army C5ISR, DOE, USABC, and NASA